Disruption of the pelvic ring due to high energy trauma can cause severe bleeding from severed blood vessels, torn ligaments and fractured bone. Active intervention with compression of the injured pelvic bones can reduce the bleeding by a tamponade effect and by stabilizing the tissues. Current methods to intervene use some type of external fixation device applied to the pelvis. One such method is the insertion of two or three threaded metal pins into each iliac crest and the attachment of a frame of rods and connectors to hold the two innominate bones together.
Another method is the use of a large C-shaped clamp placed around the pelvis with one or more pins placed through the skin against the lateral aspect of each innominate bone and then tightened into place.
These devices were devised to firmly hold the disrupted parts of the pelvic ring together. They permit surgical access to the abdomen and perineum in the event it is needed. When initially devised these metallic external fixators were often used for many weeks for the definitive treatment of pelvic injuries.
There are a number of disadvantages to using these external fixators. There is a high complication rate, including infection, loosening, and injury to blood vessels. Some time is required to apply them, delaying the benefits of resuscitation. An orthopaedic surgeon is often needed to apply them, necessitating availability and experience. Two or more incisions are required to insert them. If infection around the pins occurs, it can impede, delay or prevent a more extensive definitive operation to stabilize the pelvic ring with internal fixation.
Also, an external fixator is more often now being used only for resuscitation and thus for a brief period of time, just long enough to stabilize the patient's condition. Then internal fixation is performed. In many cases many surgeons feel that an external fixator is no longer needed.
Earlier in this century, a pelvic sling was used to hold the disrupted pelvis together. It consisted of a canvas sling the height of which was approximately the vertical dimension of the pelvis. It would be placed under the pelvis, ropes attached to fasteners on each end, and traction applied to these ropes, sometimes crossing them over. The disadvantages of the pelvic sling have led to it rarely being used at this time. It was difficult to move the patient while in bed and not possible to move the patient out of bed without losing the effectiveness of the pelvic sling. The pelvic sling did not necessarily apply sufficient compression to effectively tamponade any bleeding or stabilize the injured pelvic bones.
There is a pelvic belt (U.S. Pat. No. 5,407,422) designed for chronic instability of the sacroiliac joint or pubic symphysis. It consists of a single narrow belt with a weak hook and loop type connector that would be unlikely to hold up under trauma situations with an expanding pelvic hematoma. The height of this belt is much less than the height of the pelvis and thus gives inadequate compression to the pelvic area. The buckle can be tightened only by pulling in one direction. Thus, forceful pulling would be likely to rotate the belt and make it difficult to apply the maximum force. Support belt (U.S. Pat. No. 5,178,163) is of similar construction. Kinetic back support belt (U.S. Pat. No. 4,545,370) is also of similar construction. It has a buckle that cannot be dynamically tightened.
Other back braces are designed for support of the lumbar region, rather than the pelvis. They are contoured to fit the natural lumbar lordosis. Most are elastic in the direction of support to provide comfort and compression, but not to resist expansion. None of the braces have a ratcheting buckle or connector that can easily and rapidly be tightened. None has a buckle that is tightened by pulling on both sides so that the brace will not rotate.
For example, a back brace (U.S. Pat. No. 5,833,638) uses a relatively weak hook and loop type fastener alone and is shaped to be worn "above the iliac crests." The back brace in U.S. Pat. No. 5,776,087 is "curved to underlie the curve of the lower ribs of the body." It is constructed with stays that fit into pockets, an unnecessary and uncomfortable feature if immobilizing the pelvis. It has the feature of straps that go over the shoulders, which indicates that the brace fits loosely. A fireman's back brace (U.S. Pat. No. 5,484,395) is a "lumbar spinal support" with an elastic tensioning strap that would stretch when an expanding force is applied. A further back brace (U.S. Pat. No. 5,547,462) consists of a single narrow belt with front and back panels. The panels give insufficient support to the sides of the pelvis. It applies pressure to the back rather than posterior aspect of the pelvis and the front panel rests against the "stomach" rather than the anterior aspect of the pelvis. A conformable back brace with an abdominal support (U.S. Pat. No. 5,433,697) has abdominal and lumbar support members or panels connected with narrow straps to each side. The brace conforms by placing straps through slats in these panels. The back support disclosed in U.S. Pat. No. 4,993,409 and the simplified orthopaedic back brace in U.S. RE 34,883 consists of an elastic material with an air bladder. These are unnecessary components. The connectors are the hook and loop type. It is designed to support the lumbar region. A contour lumbar support disclosed in U.S. Pat. No. 5,267,947 is made to fit the lumbar spine and to purposely not give lateral compression. Its buckle is a standard type that cannot be dynamically adjusted. The sacro-lumbar support belt is contoured for the lower back, and has a weak hook and loop connector with unnecessary stay pockets. This configuration would be uncomfortable with the patient lying supine. It is designed to lie against the patient's back.
There are a group of devices that are used for temporary splinting of the pelvis and spine. All use a firm support to immobilize the spine but they do not allow compression of the pelvic region. Portable pelvic and leg splints (U.S. Pat. No. 4,580,555) have an extension to splint the legs. They use buckles that pull from one direction that could tend to rotate the splint. A spinal restraint device (U.S. Pat. No. 4,211,218) extends to the head and neck and has straps that go between the legs. It has buckles that are tightened in a unilateral direction. It is open anteriorly that would permit swelling in the pelvic region to protrude. Extrication and spinal restraint devices (U.S. Pat. No. 4,665,908) do have buckles that do not rotate the device, but they have especially rigid back boards. They extend to the head and neck and between the legs also.
In fact, there are no previous braces, immobilizers or the like, that are designed to care for pelvic fractures.